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External short-circuit (cell)

Verifies a fully charged cell shorted across its terminals through a near-zero external resistance does not catch fire or explode.
Clause (method) 8.1.4
Clause (pass criteria) 5.1.3
Object cell
Status vs. 2020 unchanged
Observation period 1 h at test environment temperature

Pass criteria

A battery cell, after undergoing the external short-circuit test according to 8.1.4, should not catch fire or explode.

There is no insulation requirement and no leakage/housing-crack requirement at cell level. (PDF p. 11)

Source: GB 38031-2025, clause 5.1.3 (PDF p. 11).

Pre-conditions

  • Sample: A battery cell. (8.1.4.1)
  • Active protection: Any additional active protection circuits or devices on the cell are removed. (8.1.1)
  • Starting state: Cell standard-charged per clause 7.1.1. (8.1.4.2)

Test parameters

Parameter Value Source
Pre-test charge Standard charging per 7.1.1 8.1.4.2
Short configuration Direct short between positive and negative terminals 8.1.4.3
External circuit resistance < 5 mΩ 8.1.4.3
Short duration 10 min 8.1.4.3
Observation period 1 h at test environment temperature 8.1.4.4

Procedure

  1. Confirm the test object is a single battery cell with active protection devices removed. (8.1.1, 8.1.4.1)
  2. Standard-charge the cell using the method described in clause 7.1.1. (8.1.4.2)
  3. Apply an external short circuit between the cell's positive and negative terminals. The external circuit resistance shall be less than 5 mΩ. (8.1.4.3)
  4. Maintain the short for 10 min. (8.1.4.3)
  5. Observe the cell for 1 h at the test environment temperature (22 °C ± 5 °C, per 6.1.1). (8.1.4.4)
  6. Record any fire or explosion event during the short or the observation window.

After-test observation

Observe the test object for 1 h at the test environment temperature. (8.1.4.4)

Engineering notes (non-normative)

Engineering note (non-normative): The 5 mΩ ceiling includes the bus bars, contactor contact resistance, and current-shunt insertion loss — not just a deliberate resistor. For a high-capacity cell at full SOC, a sloppy fixture often overshoots 5 mΩ, which artificially limits peak current and softens the test. Measure end-to-end with a four-wire micro-ohmmeter before each test.

Engineering note (non-normative): Peak short-circuit current can exceed 10 × I1 in the first seconds. Sense leads, contactors, and the cell's own tabs are the most common failure points before the cell itself responds — over-spec the fixture so it does not become the limiting fault.